Develop Reference

An error occurred while loading the image in VScode

I am recently developing new android project. I am trying to save image files into the server directory.
I use Retrofit for HttpConnection with server.
Storing image files into the server directory works well, but the image is not available. Everytime I upload files into the server, it says An error occurred while loading the image. I have been looking for solutions and trying to fix this problem, but I have no idea what causes this problem.
Here is my android code :
ArrayList<MultipartBody.Part> files = new ArrayList<>();
for(int a = 0; a < list.size(); a++) {
// list = uri image list for recyclerview.
RequestBody fileBody = RequestBody.create(MediaType.parse("image/jpeg"), String.valueOf(list.get(a)));
String fileName = "photo" + a + ".jpg";
MultipartBody.Part filePart = MultipartBody.Part.createFormData("uploaded_file"+a, fileName, fileBody);
files.add(filePart);
}
Call<String> uploadPost = posts.uploadPost(files,hashMap);
uploadPost.enqueue(new Callback<String>() {
#Override
public void onResponse(Call<String> call, Response<String> response) {
if(response.isSuccessful() && response.body() != null) {
Intent intent = new Intent(upload_sale.this, MainActivity.class);
startActivity(intent);
finish();
}
}
#Override
public void onFailure(Call<String> call, Throwable t) {
Log.d("upload_post",t.getMessage());
}
});
Here is the php code :
$authNum = $_POST['authNum'];
$title = $_POST['title'];
$des = $_POST['description'];
$price = $_POST['price'];
$area = $_POST['area'];
$longitude = $_POST['longitude'];
$latitude = $_POST['latitude'];
$count = $_POST['count'];
$count_int = (int)$count;
if(isset($_FILES['uploaded_file0']['name'])) {
for($i = 0; $i<$count_int; $i++) {
$basename = basename($_FILES['uploaded_file'.$i]['name']);
$file_path = $file_path . $basename;
if(isset($_FILES['uploaded_file'.$i])) {
move_uploaded_file($_FILES['uploaded_file'.$i]['tmp_name'],"./postImage/".$fn.$basename);
$query_img =
"INSERT INTO post_img(path,authNum,img_del,post_authNum)
VALUES ('http://3.36.34.173/postImage/".$fn.$basename."',$authNum,'../postImage/".$fn.$basename."','$post_authNum')
";
}
Thank you in advance.enter image description here

how to upload image Using multipart entity using retrofit in Android

i am able to upload image using postman :
but when i tried using multi-part entity using retrofit i am not able to upload that it tell file is not find in server below is my code:
public void visitrecord_existingtask(int userId, String companyId, String taskId, String actionTaken, String timeSpend, double lat, double longi, ArrayList<String> filePaths) {
MultipartBody.Builder builder = new MultipartBody.Builder();
builder.setType(MultipartBody.FORM);
builder.addFormDataPart("userid", String.valueOf(userId));
builder.addFormDataPart("companyid", companyId);
builder.addFormDataPart("taskid", taskId);
builder.addFormDataPart("task_actiontaken", actionTaken);
builder.addFormDataPart("timespent", timeSpend);
builder.addFormDataPart("latitude", String.valueOf(lat));
builder.addFormDataPart("longitude", String.valueOf(longi));
for (int i = 0; i < filePaths.size(); i++) {
File file = new File(filePaths.get(i));
builder.addFormDataPart("files", file.getName(), RequestBody.create(MediaType.parse("multipart/form-data"), file));
}
MultipartBody requestBody = builder.build();
Call<VisitrecordExistingtask> call = webAPIInterface.visitrecordExistingtask(requestBody);
call.enqueue(new Callback<VisitrecordExistingtask>() {
#Override
public void onResponse(Call<VisitrecordExistingtask> call, Response<VisitrecordExistingtask> response) {
visitrecordlistner.showLoginResult(response.code(), response.body());
}
#Override
public void onFailure(Call<VisitrecordExistingtask> call, Throwable t) {
visitrecordlistner.showError(t);
}
});
}
this is my code which i am using file upload to server i have to send soem parameter plus image file to server but its not able to find image in server can any one please suggest me what i am doing wrong .

How to make retrofit api request for each item in list with rxjava?

I'm very new to RxJava and although I have seen multiple questions related to the one I am asking, I can't seem to piece them out altogether.
I have a PostPatrol object containing the following data:
public class PostPatrol {
String checkpoint_name;
String status;
int user;
String detail;
List<String> photos;
public PostPatrol(int cpId, String checkpoint_name, String detail, List<String> photos, String detail) {
this.cpId = cpId;
this.checkpoint_name = checkpoint_name;
this.detail = detail;
this.photos = photos;
this.status = status;
}
//getters and setters
}
What I'm trying to do now is to save a local list of photos into this PostPatrol record, but before that I have to upload the photos one by one with retrofit, get back a url and save that to a list which I then set as the photos for the PostPatrol record.
Once I save all the needed details for a certain PostPatrol record, I then send that again through retrofit.
Currently, I am doing it this way:
I pass the photos to a function to upload the image one by one
The function is like this:
private void uploadImage(List<String> photos, String folder, long requestId) {
final int size = photos.size();
final long reqId = requestId;
for (String path : photos) {
File file = new File(path);
RequestBody requestBody = RequestBody.create(MediaType.parse("image/*"), file);
MultipartBody.Part body = MultipartBody.Part.createFormData("image", file.getName(), requestBody);
RequestBody folderName = RequestBody.create(MediaType.parse("text/plain"), folder);
ApiEndpointInterface apiEndpointInterface = RetrofitManager.getApiInterface();
Call<FileInfo> call4File = apiEndpointInterface.postFile(body, folderName);
call4File.enqueue(new ApiCallback<FileInfo>() {
#Override
protected void do4Failure(Throwable t) {
Log.d(TAG, t.toString());
snackbar = Snackbar.make(viewPendingRequestLayout, R.string.sb_image_upload_error, Snackbar.LENGTH_SHORT);
snackbar.show();
position++;
}
#Override
protected void do4PositiveResponse(Response<FileInfo> response) {
Log.d(TAG, "Uploaded Image");
FileInfo fileDetails = response.body();
listUrls.add(fileDetails.getImage());
position++;
if (position == size) {
postRequest(reqId);
position = 0;
}
}
#Override
protected void do4NegativeResponse(Response<FileInfo> response) {
String bodyMsg = "";
try {
bodyMsg = new String(response.errorBody().bytes());
} catch (IOException e) {
e.printStackTrace();
}
Log.d(TAG, bodyMsg);
snackbar = Snackbar.make(viewPendingRequestLayout, R.string.sb_image_upload_error, Snackbar.LENGTH_SHORT);
snackbar.show();
position++;
}
});
}
}
In do4PositiveResponse I use local variables to keep track whether I have uploaded all the photos before sending them to a function where the list is saved to the PostPatrol record. Sometimes though, I get problems where the photos aren't uploaded at all since it fires too late or too early.
This is my code onpostRequest()
private void postRequest(long requestId) {
if(mapIdPatrol.containsKey(requestId)){
PostPatrol postPatrol = mapIdPatrol.get(requestId);
postPatrol.setPhotos(listUrls);
postPatrolRequest(postPatrol, requestId);
}
listUrls = new ArrayList<>();
}
And finally my code on postPatrolRequest()
private void postPatrolRequest(final PostPatrol postPatrol, final long requestId){
ApiEndpointInterface apiEndpointInterface = RetrofitManager.getApiInterface();
Call<ResponseId> call4Handle = apiEndpointInterface.handleCheckpoint(postPatrol);
call4Handle.enqueue(new ApiCallback<ResponseId>() {
#Override
protected void do4Failure(Throwable t) {
finishUploading();
Log.d(TAG, t.toString());
}
#Override
protected void do4PositiveResponse(Response<ResponseId> response) {
RequestsDataSource.removeRequest(getApplication(),requestId);
finishUploading();
}
#Override
protected void do4NegativeResponse(Response<ResponseId> response) {
finishUploading();
String bodyMsg = "";
try {
bodyMsg = new String(response.errorBody().bytes());
} catch (IOException e) {
e.printStackTrace();
}
Log.d(TAG, bodyMsg);
snackbar = Snackbar.make(viewPendingRequestLayout, getResources().getText(R.string.sb_negative_response), Snackbar.LENGTH_SHORT);
snackbar.show();
}
});
}
I know this is very inefficient and so I would like your help so I can try to find a way around it with the use of RxJava. Thank you.

Is the operation atomic? i.e. if saving some of the photos via Retrofit fails, do you still have to proceed?
Anyway, roughly the solution will be something like that (pseudocode):
Observable<String> urls = Observable.from(listOfPhotoFilePaths)
.flatMapDelayError(path -> { return retrofit.save(readFile(path))})
.toList()
Observable<PostPatrol> pp = urls
.map(list -> { return new PostPatrol(list)})

Retrofit API to retrieve a png image

Hi I am new to Retrofit framework for Android. I could get JSON responses from REST services using it but I don't know how to download a png using retrofit. I am trying to download the png from this url:
http://wwwns.akamai.com/media_resources/globe_emea.png.
What should be response Object to be specified in the Callback<> to achieve this.

Of course we usually use Picasso to load image, but sometimes we really need use Retrofit to load a special image (like fetch a captcha image), you need add some header for request, get some value from header of response (of course you can also use Picasso + OkHttp, but in a project you have already use Retrofit to handle most of net requests), so here introduce how to implement by Retrofit 2.0.0 (I have already implemented in my project).
The key point is that you need use okhttp3.ResponseBody to receive response, else Retrofit will parse the response data as JSON, not binary data.
codes:
public interface Api {
// don't need add 'Content-Type' header, it's useless
// #Headers({"Content-Type: image/png"})
#GET
Call<ResponseBody> fetchCaptcha(#Url String url);
}
Call<ResponseBody> call = api.fetchCaptcha(url);
call.enqueue(new Callback<ResponseBody>() {
#Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
if (response.isSuccessful()) {
if (response.body() != null) {
// display the image data in a ImageView or save it
Bitmap bmp = BitmapFactory.decodeStream(response.body().byteStream());
imageView.setImageBitmap(bmp);
} else {
// TODO
}
} else {
// TODO
}
}
#Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
// TODO
}
});

As mentioned you shouldn't use Retrofit to actually download the image itself. If your goal is to simply download the content without displaying it then you could simply use an Http client like OkHttp which is another one of Square's libraries.
Here's a few lines of code which would have you download this image. You could then read the data from the InputStream.
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url("http://wwwns.akamai.com/media_resources/globe_emea.png")
.build();
client.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(Request request, IOException e) {
System.out.println("request failed: " + e.getMessage());
}
#Override
public void onResponse(Response response) throws IOException {
response.body().byteStream(); // Read the data from the stream
}
});
Even though Retrofit isn't the man for the job to answer your question, the signature of your Interface definition would like this. But again don't do this.
public interface Api {
#GET("/media_resources/{imageName}")
void getImage(#Path("imageName") String imageName, Callback<Response> callback);
}

Declare it returning Call for instance:
#GET("/api/{api}/bla/image.png")
Call<ResponseBody> retrieveImageData();
then convert it to Bitmap yourself:
ResponseBody body = retrofitService.retrieveImageData().execute().body();
byte[] bytes = body.bytes();
Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);

Retrofit is a REST library, you can use Retrofit only to get image URL but for displaying Image you should use Picasso: http://square.github.io/picasso/

Details
Android studio 3.1.4
Kotlin 1.2.60
Retrofit 2.4.0
checked in minSdkVersion 19
Solution
object RetrofitImage
object RetrofitImage {
private fun provideRetrofit(): Retrofit {
return Retrofit.Builder().baseUrl("https://google.com").build()
}
private interface API {
#GET
fun getImageData(#Url url: String): Call<ResponseBody>
}
private val api : API by lazy { provideRetrofit().create(API::class.java) }
fun getBitmapFrom(url: String, onComplete: (Bitmap?) -> Unit) {
api.getImageData(url).enqueue(object : retrofit2.Callback<ResponseBody> {
override fun onFailure(call: Call<ResponseBody>?, t: Throwable?) {
onComplete(null)
}
override fun onResponse(call: Call<ResponseBody>?, response: Response<ResponseBody>?) {
if (response == null || !response.isSuccessful || response.body() == null || response.errorBody() != null) {
onComplete(null)
return
}
val bytes = response.body()!!.bytes()
onComplete(BitmapFactory.decodeByteArray(bytes, 0, bytes.size))
}
})
}
}
Usage 1
RetrofitImage.getBitmapFrom(ANY_URL_STRING) {
// "it" - your bitmap
print("$it")
}
Usage 2
Extension for ImageView
fun ImageView.setBitmapFrom(url: String) {
val imageView = this
RetrofitImage.getBitmapFrom(url) {
val bitmap: Bitmap?
bitmap = if (it != null) it else {
// create empty bitmap
val w = 1
val h = 1
val conf = Bitmap.Config.ARGB_8888
Bitmap.createBitmap(w, h, conf)
}
Looper.getMainLooper().run {
imageView.setImageBitmap(bitmap!!)
}
}
}
Usage of the extension
imageView?.setBitmapFrom(ANY_URL_STRING)

You could also use Retrofit to perform the #GET and just return the Response. Then in code you can do isr = new BufferedInputStream(response.getBody().in()) to get the input stream of the image and write it into a Bitmap, say, by doing BitmapFactory.decodeStream(isr).

I hope following code will help you:
Include following function inside MainActivity.java:
void getRetrofitImage() {
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(url)
.addConverterFactory(GsonConverterFactory.create())
.build();
RetrofitImageAPI service = retrofit.create(RetrofitImageAPI.class);
Call<ResponseBody> call = service.getImageDetails();
call.enqueue(new Callback<ResponseBody>() {
#Override
public void onResponse(Response<ResponseBody> response, Retrofit retrofit) {
try {
Log.d("onResponse", "Response came from server");
boolean FileDownloaded = DownloadImage(response.body());
Log.d("onResponse", "Image is downloaded and saved ? " + FileDownloaded);
} catch (Exception e) {
Log.d("onResponse", "There is an error");
e.printStackTrace();
}
}
#Override
public void onFailure(Throwable t) {
Log.d("onFailure", t.toString());
}
});
}
Following is the file handling code for image:
private boolean DownloadImage(ResponseBody body) {
try {
Log.d("DownloadImage", "Reading and writing file");
InputStream in = null;
FileOutputStream out = null;
try {
in = body.byteStream();
out = new FileOutputStream(getExternalFilesDir(null) + File.separator + "AndroidTutorialPoint.jpg");
int c;
while ((c = in.read()) != -1) {
out.write(c);
}
}
catch (IOException e) {
Log.d("DownloadImage",e.toString());
return false;
}
finally {
if (in != null) {
in.close();
}
if (out != null) {
out.close();
}
}
int width, height;
ImageView image = (ImageView) findViewById(R.id.imageViewId);
Bitmap bMap = BitmapFactory.decodeFile(getExternalFilesDir(null) + File.separator + "AndroidTutorialPoint.jpg");
width = 2*bMap.getWidth();
height = 6*bMap.getHeight();
Bitmap bMap2 = Bitmap.createScaledBitmap(bMap, width, height, false);
image.setImageBitmap(bMap2);
return true;
} catch (IOException e) {
Log.d("DownloadImage",e.toString());
return false;
}
}
This is done using Android Retrofit 2.0. I hope it helped you.
Source: Image Download using Retrofit 2.0

Retrofit is encoding your byte array to base 64. So decode your string and you are good to go. In this way you can retrieve a list of images.
public static Bitmap getBitmapByEncodedString(String base64String) {
String imageDataBytes = base64String.substring(base64String.indexOf(",")+1);
InputStream stream = new ByteArrayInputStream(Base64.decode(imageDataBytes.getBytes(), Base64.DEFAULT));
return BitmapFactory.decodeStream(stream);
}

Easy & Best solution
If API response is image, no need to use retrofit to fetch image. Using GlideUrl image can rendered easily with Glide
val glideUrl = GlideUrl("APICall url",LazyHeaders.Builder()
.addHeader("X-Api-Key", "apiKey") // if any headers are required
.build())
Glide.with(requireContext()).load(glideUrl).into(imageview)

How to create nanohttpd server in android?

Actually ,I had searched some questions and go to the github. But I'm new ,I cannot understand the example.
I want to create the http server in android so I can access it in PC browser.
I had instance a class extend nanohttpd, but the server just don't work. I don't know why ,my computer and phone are in the same WIFI,uh.....
public class MyHTTPD extends NanoHTTPD {
/**
* Constructs an HTTP server on given port.
*/
public MyHTTPD()throws IOException {
super(8080);
}
#Override
public Response serve( String uri, Method method,
Map<String, String> header, Map<String, String> parms,
Map<String, String> files )
{
System.out.println( method + " '222" + uri + "' " );
String msg = "<html><body><h1>Hello server</h1>\n";
if ( parms.get("username") == null )
msg +=
"<form action='?' method='get'>\n" +
" <p>Your name: <input type='text' name='username'></p>\n" +
"</form>\n";
else
msg += "<p>Hello, " + parms.get("username") + "!</p>";
msg += "</body></html>\n";
return new NanoHTTPD.Response(msg );
}
public static void main( String[] args )
{
try
{
new MyHTTPD();
}
catch( IOException ioe )
{
System.err.println( "Couldn't start server:\n" + ioe );
System.exit( -1 );
}
System.out.println( "Listening on port 8080. Hit Enter to stop.\n" );
try { System.in.read(); } catch( Throwable t ) {
System.out.println("read error");
};
}
}

Your sample code is missing one small detail - you create the server but you never call the "start()" method which kicks it off to listen for incoming connections. In your main() method, you could write
(new MyHTTPD()).start();
and all would be well, your server would respond the way you hoped it would.
The reason it works that way is twofold: I want the constructor to be a cheap, inexpensive operation, without side-effects. For instance, while unit testing, I call "start()" in the setup and "stop()" in the teardown methods of my jUnit test.

This is the code working for me, but I have different version of NANOHTTPD, I don't have time right now to test out your solution. Here is UploadServer class and Nano class. I return file-upload.htm from sdcard/Discover Control/Web path
public class UploadServer extends NanoHTTPD {
public UploadServer() throws IOException {
super(8080, new File("."));
}
public Response serve( String uri, String method, Properties header, Properties parms, Properties files ) {
File rootsd = Environment.getExternalStorageDirectory();
File path = new File(rootsd.getAbsolutePath() + "/Discover Control/Web");
Response r = super.serveFile("/file-upload.htm", header, path, true);
return r;
}
}
NanoHttpd class
NanoHTTPD.java
FILE UPLOAD
file-upload.htm
Hope this helps and enjoy your work.

Android Activities have a lifecycle and do not use a main() function.
If you want to start and stop the webserver as part of the Activity then you need call start and stop
in onPause and onResume, ie
public class MyActivity extends Activity {
private MyHTTPD mServer;
#Override
protected void onResume() {
super.onResume();
try {
mServer = new MyHTTPD();
mServer.start();
} catch (IOException e) {
e.printStackTrace();
mServer = null;
}
#Override
protected void onPause() {
super.onPause();
if(mServer != null) {
mServer.stop();
mServer = null;
}
}
}
An alternative is to implement the webserver as part of a Service.
In an app I'm working I have a requirement to keep the webserver running even if the user leaves the app. The only way to do this is to start and stop the webserver as part of a long-running Service that is not bound to the Activity. See Vogella's great tutorial on Android Services.

This code working for fine viewing html pages with css class which are in my assesst folders
androidWebServer.start();
this will start the server below code for server functions
public class AndroidWebServer extends NanoHTTPD {
Realm realm;
Map<String, String> parms;
DBHelper db = new DBHelper(OpenRAP.getContext());
boolean isStartedHS = MainActivity.isStartedHS;
private AsyncHttpServer server = new AsyncHttpServer();
private AsyncServer mAsyncServer = new AsyncServer();
private String TAG = "androidwebserver";
Storage storage = new Storage(OpenRAP.getContext());
public AndroidWebServer(int port) {
super(port);
}
public AndroidWebServer(String hostname, int port) {
super(hostname, port);
}
#Override
public String getHostname() {
return super.getHostname();
}
#Override
public Response serve(IHTTPSession session) {
Method method = session.getMethod();
String uri = session.getUri();
Map<String, String> files = new HashMap<>();
SharedPreferences prefs = OpenRAP.getContext().getSharedPreferences(MainActivity.mypreference, MODE_PRIVATE);
OpenRAP app = (OpenRAP) OpenRAP.getContext();
Storage storage = new Storage(OpenRAP.getContext());
String currentpath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/www/";
String temp = Environment.getExternalStorageDirectory().getAbsolutePath() + "/www/temp/";
String ecarpath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/www/ecars_files/";
String xcontent = Environment.getExternalStorageDirectory().getAbsolutePath() + "/www/xcontent/";
String Endpoint = session.getUri();
if (Endpoint.equals("/")) {
String answer = "";
try {
// Open file from SD Card
File root = Environment.getExternalStorageDirectory().getAbsoluteFile();
FileReader index = new FileReader(root +
"/www/openrap/index.html");
BufferedReader reader = new BufferedReader(index);
String line = "";
while ((line = reader.readLine()) != null) {
answer += line;
}
reader.close();
} catch (IOException ioe) {
Log.w("Httpd", ioe.toString());
}
return newFixedLengthResponse(answer);
}